#--- # Excerpted from "Agile Web Development with Rails", # published by The Pragmatic Bookshelf. # Copyrights apply to this code. It may not be used to create training material, # courses, books, articles, and the like. Contact us if you are in doubt. # We make no guarantees that this code is fit for any purpose. # Visit http://www.pragmaticprogrammer.com/titles/rails4 for more book information. #--- #--- # Excerpted from "Agile Web Development with Rails, 4rd Ed.", # published by The Pragmatic Bookshelf. # Copyrights apply to this code. It may not be used to create training material, # courses, books, articles, and the like. Contact us if you are in doubt. # We make no guarantees that this code is fit for any purpose. # Visit http://www.pragmaticprogrammer.com/titles/rails4 for more book information. #--- $: << File.dirname(__FILE__) require "connect" require "rubygems" require "active_record" ActiveRecord::Schema.define do create_table :orders, :force => true do |t| t.integer :user_id t.string :name t.string :address t.string :email end create_table :users, :force => :true do |t| t.string :name end end class ActiveRecord::Base def self.encrypt(*attr_names) encrypter = Encrypter.new(attr_names) before_save encrypter after_save encrypter after_find encrypter define_method(:after_find) { } end end class Encrypter # We're passed a list of attributes that should # be stored encrypted in the database def initialize(attrs_to_manage) @attrs_to_manage = attrs_to_manage end # Before saving or updating, encrypt the fields using the NSA and # DHS approved Shift Cipher def before_save(model) @attrs_to_manage.each do |field| model[field].tr!("a-z", "b-za") end end # After saving, decrypt them back def after_save(model) @attrs_to_manage.each do |field| model[field].tr!("b-za", "a-z") end end # Do the same after finding an existing record alias_method :after_find, :after_save end class Order < ActiveRecord::Base encrypt(:name, :email) end o = Order.new o.name = "Dave Thomas" o.address = "123 The Street" o.email = "dave@example.com" o.save puts o.name o = Order.find(o.id) puts o.name